The Influence of Depression on Cognitive Decline in Community-Dwelling Elderly Persons

Abstract

An association between depression and cognitive decline (CD) has been observed in cross-sectional and case/control studies of elderly populations. Whereas a handful of longitudinal community studies have found depressive symptoms to predate the onset of CD, others have found no association between depression and subsequent cognitive dysfunction. The authors examined the association between depressive symptoms and cognitive errors measured 3 years apart in a longitudinal sample of community-dwelling elderly persons. Data were obtained from 4,162 subjects assessed as part of the Established Populations for Epidemiologic Studies of the Elderly, a population survey assessing physical, psychological, and social functioning of persons 65 years and older. Depressive symptoms were associated with subsequent CD even after controlling for baseline cognitive status, as well as demographic (e.g., race, gender, age, and socioeconomic status) and physical functioning variables. This was true for the sample as a whole, as well as for a subsample of participants who evidenced no baseline cognitive difficulties. Study results are consistent with others finding an association between depressive symptoms and subsequent CD. Theories regarding the causal mechanisms underlying the association between depression and cognitive decline are discussed.